| Literature DB >> 35317017 |
Julius J Okello1, Jolien Swanckaert2, Daniel Martin-Collado3, Bruno Santos4, Benard Yada5, Robert O M Mwanga1, Anouk Schurink4, Michael Quinn6, Graham Thiele7, Simon Heck8, Timothy J Byrne9, Guy G Hareau7, Hugo Campos7.
Abstract
Crop breeding programs must accelerate crop improvement, spur widespread adoption of new varieties and increase variety turnover they are to meet the diverse needs of their clients. More comprehensive quantitative approaches are needed to better inform breeding programs about the preferred traits among farmers and other actors. However, the ability of current breeding programs to meet the demands of their clients is limited by the lack of insights about value chain actor preference for individual or packages of traits. Ranking traits based on monetary incentives, rather than subjective values, represents a more comprehensive, consistent, and quantitative approach to inform breeding programs. We conducted a large pilot in Uganda to assess the implementation of a novel approach to trait ranking, using a uniquely large sample of diverse sweetpotato value chain actors. We found meaningful differences in trait ranking and heterogeneity among different actors using this approach. We also show our approach's effectiveness at uncovering unmet demand for root quality traits and at characterizing the substantial trait demand heterogeneity among value chain players. Implementing this approach more broadly for sweetpotato and other crops would increase the effectiveness of breeding programs to improve food security in developing countries.Entities:
Keywords: Uganda; crop breeding; economic incentives; sweetpotato; trait ranking
Year: 2022 PMID: 35317017 PMCID: PMC8934386 DOI: 10.3389/fpls.2022.808597
Source DB: PubMed Journal: Front Plant Sci ISSN: 1664-462X Impact factor: 5.753
FIGURE 1Picture of raw sweetpotato intact storage roots and cut inside surfaces: most households consume steamed roots.
FIGURE 2Trait preference1 ranks of 13 sweetpotato traits included in the lOOOMinds® survey used to generate economic selection index in Uganda (for all respondents). Each gray dot represents an individual answer (respondent preference for each trait) and the blue doc represents the average preference rank of a trait, ordered from most (left) to least prefened Different letter- denote significant (p-value < 0.05) differences between the traits.
FIGURE 3Principal component analysis (PCA) plot separating respondents based on actor type and their preference for sweetpotato traits in Uganda. The numbers represent the group the respondent was assigned to (1 = “productive output” group. 2 = “plant robustness” group, and 3 = “root quality” group); Dry matter = hardness of roots after cooking, flesh color = flesh color of roots, maturin’ time = days to maturin’, shelflife = storage shelflife, SPVD resistance = sweetpotato virus disease resistance, sweetness = flesh sweetness, weevil resistance = sweet potato weevil resistance.
Average trait preference ranks of sweetpotato traits by value chain actors in Uganda, by cluster1 of value chain actors.
| Average preference rank | ||||||
| Trait | Across groups | Productive output ( | Plant robustness ( | Root quality ( | P-value | |
| Vine survival | 3.50 | 2.99a | 3.06a | 6.48b | < 2 × 10–16 | |
| Sweet potato Weevil resistance | 4.61 | 4.31a | 3.15b | 9.23c | < 2 × 10–16 | |
| Sweet potato Virus Disease resistance | 4.73 | 4.27a | 3.09b | 10.32c | < 2 × 10–16 | |
| Storage shelf life | 5.67 | 5.06a | 6.56b | 5.85c | 6.1 × 10–14 | |
| Fresh root yield | 6.54 | 5.61a | 7.81b | 6.91c | < 2 × 10–16 | |
| Root shape | 7.90 | 8.38a | 7.53b | 7.02b | 7.4 × 10–9 | |
| Root size | 7.92 | 8.22a | 7.98a | 6.76b | 6.3 × 10–8 | |
| Days to maturity | 8.01 | 5.86a | 10.46b | 10.05b | < 2 × 10–16 | |
| Flesh sweetness | 8.61 | 10.22a | 7.63b | 4.96c | < 2 × 10–16 | |
| Skin smoothness | 9.09 | 10.51a | 8.29b | 5.83c | < 2 × 10–16 | |
| Hardness of roots after cooking | 9.15 | 10.87a | 8.28b | 4.90c | < 2 × 10–16 | |
| Flesh color of roots | 10.14 | 11.43a | 10.08b | 5.57c | < 2 × 10–16 | |
| Vine yield | 10.42 | 9.44a | 11.60b | 11.24b | < 2 × 10–16 | |
Variables that explain differences in ranking between cluster groups of sweetpotato value chain actors in Uganda.
| Variable | Definition | Productive output | Plant robustness | Root quality | p-value |
| Actor type | Consumer (%, | 15 | 32 | 53 | |
| Processor (%, | 41 | 47 | 12 | ||
| Root producer (%, | 61 | 32 | 7 | ||
| Trader (%, | 23 | 45 | 32 | ||
| Vine multiplier (%, | 41 | 50 | 9 |
*P-values are from the Fisher’s Exact Test for count data (fisher.test function in R software) calculated across the clusters.
Economic values of traits in survey units (EV), unit transformation factors (ut), and in breeding program units (EV) generated from the economic selection index approach for sweetpotato value chain actors in Uganda.
| Trait | Selection index | |||||
| EVS | ut | EVBP | EVBP productive output index | EVBP plant robustness index | EVBP root quality index | |
| Vine survival (%) | +2,285 | +1.00 | +2,285 | +19,183 | +26,196 | +22,371 |
| Sweetpotato weevil resistance (1–9 score) | –2,078 | +12.50 | –25,975 | –5,687 | –8,842 | –6,015 |
| Sweetpotato virus disease resistance (%) | –2,043 | +1.00 | –2,043 | –1,901 | –2,912 | –1,435 |
| Storage shelf life (week) | +1,111 | +7.00 | +7,777 | +6,594 | +8,008 | +11,480 |
| Fresh root yield (tons/ha) | +5,748 | +4.05 | +23,261 | +64,157 | +71,658 | +105,394 |
| Root shape (1–9 score) | +419 | –12.50 | –5,238 | –2,384 | –3,674 | –5,573 |
| Storage root size (1–9 score) | +427 | –12.50 | –5,338 | –2,631 | –3,955 | –6,408 |
| Days to maturity (days) | –1,165 | +1.00 | –1,165 | –3,737 | –2,734 | –3,194 |
| Flesh sweetness (1–9 score) | +10,661 | +0.44 | +4,738 | +3,570 | +7,702 | +14,495 |
| Skin smoothness | +9,595 | - | - | - | - | - |
| Hardness of roots after cooking (1–9 score) | +10,143 | +0.50 | +5,072 | +3,111 | +6,999 | +15,305 |
| Flesh color of roots (1–30 score) | +8,578 | +0.14 | +1,183 | +4,160 | +8,245 | +21,492 |
| Vine yield (tons/ha) | +835 | +13.49 | +11,264 | +124,729 | +111,766 | +121,416 |
FIGURE 4Relative emphasis (RE) of sweetpotato traits from the application of economic selection approach using survey data collected from value chain actors in Uganda. (A) Overall RE for sweetpotato traits. (B) Productive output. (C) Plant robustness. (D) Root quality. Traits in this panels (A–D) legends are ordered from highest to lowest contribution to genetic progress within each category of traits. Production traits are labeled in diminishing gray, according to their contribution. Plant robustness traits are labeled in diminishing red, and root quality traits in diminishing green. Data on skin smoothness and storage shelf life was missing and hence this trait was dropped.
Relative emphasis (%) on production, plant robustness, and root quality for the overall index and the productive output, plant robustness, and root quality indices generated from the economic selection index approach.
| Relative emphasis (%) per trait category | Overall index | Productive output index | Plant robustness index | Root quality index |
| Productive output | 77.0 |
| 73.1 | 71.2 |
| Plant robustness | 12.2 | 11.4 |
| 9.2 |
| Root quality | 10.8 | 6.7 | 12.0 |
|
Bold numbers denote highest relative emphasis in percentage terms.